mehdi : changing updateFires

src/main/java/app/SimulatorApplication.java

src/main/java/controller/Controller.java

src/main/java/model/FirefighterBoard.java

src/main/java/model/ModelElement.java

src/main/java/model/Road.java

src/main/java/view/ViewElement.java

src/test/java/model/FirefighterBoardTest.java